| /* |
| * Copyright IBM Corporation, 2010 |
| * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of version 2.1 of the GNU Lesser General Public License |
| * as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it would be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/fs.h> |
| #include <net/9p/9p.h> |
| #include <net/9p/client.h> |
| #include <linux/slab.h> |
| #include <linux/sched.h> |
| #include <linux/posix_acl_xattr.h> |
| #include "xattr.h" |
| #include "acl.h" |
| #include "v9fs.h" |
| #include "v9fs_vfs.h" |
| |
| static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name) |
| { |
| ssize_t size; |
| void *value = NULL; |
| struct posix_acl *acl = NULL; |
| |
| size = v9fs_fid_xattr_get(fid, name, NULL, 0); |
| if (size > 0) { |
| value = kzalloc(size, GFP_NOFS); |
| if (!value) |
| return ERR_PTR(-ENOMEM); |
| size = v9fs_fid_xattr_get(fid, name, value, size); |
| if (size > 0) { |
| acl = posix_acl_from_xattr(value, size); |
| if (IS_ERR(acl)) |
| goto err_out; |
| } |
| } else if (size == -ENODATA || size == 0 || |
| size == -ENOSYS || size == -EOPNOTSUPP) { |
| acl = NULL; |
| } else |
| acl = ERR_PTR(-EIO); |
| |
| err_out: |
| kfree(value); |
| return acl; |
| } |
| |
| int v9fs_get_acl(struct inode *inode, struct p9_fid *fid) |
| { |
| int retval = 0; |
| struct posix_acl *pacl, *dacl; |
| struct v9fs_session_info *v9ses; |
| |
| v9ses = v9fs_inode2v9ses(inode); |
| if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) || |
| ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) { |
| set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL); |
| set_cached_acl(inode, ACL_TYPE_ACCESS, NULL); |
| return 0; |
| } |
| /* get the default/access acl values and cache them */ |
| dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT); |
| pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS); |
| |
| if (!IS_ERR(dacl) && !IS_ERR(pacl)) { |
| set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl); |
| set_cached_acl(inode, ACL_TYPE_ACCESS, pacl); |
| } else |
| retval = -EIO; |
| |
| if (!IS_ERR(dacl)) |
| posix_acl_release(dacl); |
| |
| if (!IS_ERR(pacl)) |
| posix_acl_release(pacl); |
| |
| return retval; |
| } |
| |
| static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type) |
| { |
| struct posix_acl *acl; |
| /* |
| * 9p Always cache the acl value when |
| * instantiating the inode (v9fs_inode_from_fid) |
| */ |
| acl = get_cached_acl(inode, type); |
| BUG_ON(acl == ACL_NOT_CACHED); |
| return acl; |
| } |
| |
| int v9fs_check_acl(struct inode *inode, int mask) |
| { |
| struct posix_acl *acl; |
| struct v9fs_session_info *v9ses; |
| |
| v9ses = v9fs_inode2v9ses(inode); |
| if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) || |
| ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) { |
| /* |
| * On access = client and acl = on mode get the acl |
| * values from the server |
| */ |
| return -EAGAIN; |
| } |
| acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS); |
| |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| if (acl) { |
| int error = posix_acl_permission(inode, acl, mask); |
| posix_acl_release(acl); |
| return error; |
| } |
| return -EAGAIN; |
| } |
| |
| static int v9fs_set_acl(struct dentry *dentry, int type, struct posix_acl *acl) |
| { |
| int retval; |
| char *name; |
| size_t size; |
| void *buffer; |
| struct inode *inode = dentry->d_inode; |
| |
| set_cached_acl(inode, type, acl); |
| |
| if (!acl) |
| return 0; |
| |
| /* Set a setxattr request to server */ |
| size = posix_acl_xattr_size(acl->a_count); |
| buffer = kmalloc(size, GFP_KERNEL); |
| if (!buffer) |
| return -ENOMEM; |
| retval = posix_acl_to_xattr(acl, buffer, size); |
| if (retval < 0) |
| goto err_free_out; |
| switch (type) { |
| case ACL_TYPE_ACCESS: |
| name = POSIX_ACL_XATTR_ACCESS; |
| break; |
| case ACL_TYPE_DEFAULT: |
| name = POSIX_ACL_XATTR_DEFAULT; |
| break; |
| default: |
| BUG(); |
| } |
| retval = v9fs_xattr_set(dentry, name, buffer, size, 0); |
| err_free_out: |
| kfree(buffer); |
| return retval; |
| } |
| |
| int v9fs_acl_chmod(struct dentry *dentry) |
| { |
| int retval = 0; |
| struct posix_acl *acl; |
| struct inode *inode = dentry->d_inode; |
| |
| if (S_ISLNK(inode->i_mode)) |
| return -EOPNOTSUPP; |
| acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS); |
| if (acl) { |
| retval = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode); |
| if (retval) |
| return retval; |
| retval = v9fs_set_acl(dentry, ACL_TYPE_ACCESS, acl); |
| posix_acl_release(acl); |
| } |
| return retval; |
| } |
| |
| int v9fs_set_create_acl(struct dentry *dentry, |
| struct posix_acl **dpacl, struct posix_acl **pacl) |
| { |
| if (dentry) { |
| v9fs_set_acl(dentry, ACL_TYPE_DEFAULT, *dpacl); |
| v9fs_set_acl(dentry, ACL_TYPE_ACCESS, *pacl); |
| } |
| posix_acl_release(*dpacl); |
| posix_acl_release(*pacl); |
| *dpacl = *pacl = NULL; |
| return 0; |
| } |
| |
| int v9fs_acl_mode(struct inode *dir, mode_t *modep, |
| struct posix_acl **dpacl, struct posix_acl **pacl) |
| { |
| int retval = 0; |
| mode_t mode = *modep; |
| struct posix_acl *acl = NULL; |
| |
| if (!S_ISLNK(mode)) { |
| acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT); |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| if (!acl) |
| mode &= ~current_umask(); |
| } |
| if (acl) { |
| struct posix_acl *clone; |
| |
| if (S_ISDIR(mode)) |
| *dpacl = posix_acl_dup(acl); |
| clone = posix_acl_clone(acl, GFP_NOFS); |
| posix_acl_release(acl); |
| if (!clone) |
| return -ENOMEM; |
| |
| retval = posix_acl_create_masq(clone, &mode); |
| if (retval < 0) { |
| posix_acl_release(clone); |
| goto cleanup; |
| } |
| if (retval > 0) |
| *pacl = clone; |
| else |
| posix_acl_release(clone); |
| } |
| *modep = mode; |
| return 0; |
| cleanup: |
| return retval; |
| |
| } |
| |
| static int v9fs_remote_get_acl(struct dentry *dentry, const char *name, |
| void *buffer, size_t size, int type) |
| { |
| char *full_name; |
| |
| switch (type) { |
| case ACL_TYPE_ACCESS: |
| full_name = POSIX_ACL_XATTR_ACCESS; |
| break; |
| case ACL_TYPE_DEFAULT: |
| full_name = POSIX_ACL_XATTR_DEFAULT; |
| break; |
| default: |
| BUG(); |
| } |
| return v9fs_xattr_get(dentry, full_name, buffer, size); |
| } |
| |
| static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name, |
| void *buffer, size_t size, int type) |
| { |
| struct v9fs_session_info *v9ses; |
| struct posix_acl *acl; |
| int error; |
| |
| if (strcmp(name, "") != 0) |
| return -EINVAL; |
| |
| v9ses = v9fs_dentry2v9ses(dentry); |
| /* |
| * We allow set/get/list of acl when access=client is not specified |
| */ |
| if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) |
| return v9fs_remote_get_acl(dentry, name, buffer, size, type); |
| |
| acl = v9fs_get_cached_acl(dentry->d_inode, type); |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| if (acl == NULL) |
| return -ENODATA; |
| error = posix_acl_to_xattr(acl, buffer, size); |
| posix_acl_release(acl); |
| |
| return error; |
| } |
| |
| static int v9fs_remote_set_acl(struct dentry *dentry, const char *name, |
| const void *value, size_t size, |
| int flags, int type) |
| { |
| char *full_name; |
| |
| switch (type) { |
| case ACL_TYPE_ACCESS: |
| full_name = POSIX_ACL_XATTR_ACCESS; |
| break; |
| case ACL_TYPE_DEFAULT: |
| full_name = POSIX_ACL_XATTR_DEFAULT; |
| break; |
| default: |
| BUG(); |
| } |
| return v9fs_xattr_set(dentry, full_name, value, size, flags); |
| } |
| |
| |
| static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name, |
| const void *value, size_t size, |
| int flags, int type) |
| { |
| int retval; |
| struct posix_acl *acl; |
| struct v9fs_session_info *v9ses; |
| struct inode *inode = dentry->d_inode; |
| |
| if (strcmp(name, "") != 0) |
| return -EINVAL; |
| |
| v9ses = v9fs_dentry2v9ses(dentry); |
| /* |
| * set the attribute on the remote. Without even looking at the |
| * xattr value. We leave it to the server to validate |
| */ |
| if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) |
| return v9fs_remote_set_acl(dentry, name, |
| value, size, flags, type); |
| |
| if (S_ISLNK(inode->i_mode)) |
| return -EOPNOTSUPP; |
| if (!inode_owner_or_capable(inode)) |
| return -EPERM; |
| if (value) { |
| /* update the cached acl value */ |
| acl = posix_acl_from_xattr(value, size); |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| else if (acl) { |
| retval = posix_acl_valid(acl); |
| if (retval) |
| goto err_out; |
| } |
| } else |
| acl = NULL; |
| |
| switch (type) { |
| case ACL_TYPE_ACCESS: |
| name = POSIX_ACL_XATTR_ACCESS; |
| if (acl) { |
| mode_t mode = inode->i_mode; |
| retval = posix_acl_equiv_mode(acl, &mode); |
| if (retval < 0) |
| goto err_out; |
| else { |
| struct iattr iattr; |
| if (retval == 0) { |
| /* |
| * ACL can be represented |
| * by the mode bits. So don't |
| * update ACL. |
| */ |
| acl = NULL; |
| value = NULL; |
| size = 0; |
| } |
| /* Updte the mode bits */ |
| iattr.ia_mode = ((mode & S_IALLUGO) | |
| (inode->i_mode & ~S_IALLUGO)); |
| iattr.ia_valid = ATTR_MODE; |
| /* FIXME should we update ctime ? |
| * What is the following setxattr update the |
| * mode ? |
| */ |
| v9fs_vfs_setattr_dotl(dentry, &iattr); |
| } |
| } |
| break; |
| case ACL_TYPE_DEFAULT: |
| name = POSIX_ACL_XATTR_DEFAULT; |
| if (!S_ISDIR(inode->i_mode)) { |
| retval = acl ? -EINVAL : 0; |
| goto err_out; |
| } |
| break; |
| default: |
| BUG(); |
| } |
| retval = v9fs_xattr_set(dentry, name, value, size, flags); |
| if (!retval) |
| set_cached_acl(inode, type, acl); |
| err_out: |
| posix_acl_release(acl); |
| return retval; |
| } |
| |
| const struct xattr_handler v9fs_xattr_acl_access_handler = { |
| .prefix = POSIX_ACL_XATTR_ACCESS, |
| .flags = ACL_TYPE_ACCESS, |
| .get = v9fs_xattr_get_acl, |
| .set = v9fs_xattr_set_acl, |
| }; |
| |
| const struct xattr_handler v9fs_xattr_acl_default_handler = { |
| .prefix = POSIX_ACL_XATTR_DEFAULT, |
| .flags = ACL_TYPE_DEFAULT, |
| .get = v9fs_xattr_get_acl, |
| .set = v9fs_xattr_set_acl, |
| }; |